Synthesis of 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines and 2-(3-hydroxybutyl)-1-pyrroline using α-lithiated 2-methyl-1-pyrroline

Condensation of 2-methyl-1-pyrroline with chloroacetone or 3-chloro-2-butanone using LDA in THF afforded novel 2-(3-hydroxy-2-methyl-1-alkenyl)-1-pyrrolines via a peculiar reaction mechanism instead of the anticipated 2-(3-oxobutyl)-1-pyrrolines. The intermediacy of 2-(2,3-epoxy-2-methylalkyl)-1-pyrrolines in the latter transformation was demonstrated by immediate reductive epoxide ring opening utilizing lithium aluminium hydride in diethyl ether. Furthermore, 2-(3-oxobutyl)-1-pyrroline was prepared via an alternative approach through alkylation of 2-methyl-1-pyrroline with 3-chloro-2-(methoxymethyloxy)-1-propene using LDA in THF, followed by acid hydrolysis. Reduction of 2-(3-oxobutyl)-1-pyrroline by sodium borohydride in methanol afforded the corresponding 2-(3-hydroxybutyl)-1-pyrroline in good yield.     

Hydrolysis Reactions and Resolution of (±)-2-Acetamido-3-hydroxy-1-(4-nitrophenyl)-1-propanone

IntroductionChloramphenicol,which was isolated fromStreptomyces venezuelae in 1 947[1] ,is used as abroad- spectrum antibiotic possessing activityagainst many Gram- negative and Gram- positivemicroorganisms. (± ) - 2 - Acetamido- 3 - hydroxy- 1 -(4- nitrophenyl) - 1 - propanone[(± ) - 1 ]is one of theintermediates of producing chloramphenicol.Petrow et al.[2 ] reported some transformations of(± ) - 1 in hydrolysis reactions. However,thereaction products were complicated under multiplehydr…     

Crystal Structure of Methyl 3- (2-chlorophenyl )-3- (5, 5-dimethyl-3-hydroxy-2-cyclohexene- 1-one-2-yl) propionate

1INTRODUCTIONInorganicsolidsupportsascatalystshavebeenwellstudied,becauseoftheirap-plicationsinorganicsynthese('~".Recently,wehavereportedtheKnoevenagelcon-densationcatalysedbyKF-Al,O,['i.Inthispaper,wediscussedthecrystalstruc-tureofthetitlecomPoundsynthesizedbythereactionof2-chlorobenzaldehydey5,5-dimethyl-1,3-cyclohexanedioneandisopropylidenemalonateinmethanolcatalyzedbyKF-Alzo,'Inordertoconfirmthestructureofthetitlecompound,theX-raycrys-tallOgraphicstudywascarriedout.2EXPER1MEN…     

Enantiogenic synthesis of (R)-(−)-3-hydroxy-1-penten-4-one

Condensation of pyruvate and acrolein with whole cells of baker's yeast resulted in a mixture of 3-hydroxy-1-penten-4-one 1 and 4-hydroxy-1-penten-3-one 2. The absolute configuration (R) and the enantiomeric excess (ee 72%) of the compound 1 were determined.     

Synthesis of 3-chloro-N′-(2-hydroxy-6-pentadecylbenzylidene)benzothiophene-2-carbohydrazide

3-Chloro-N′-(2-hydroxy-6-pentadecylbenzylidene)benzothiophene-2-carbohydrazide has been synthesized by the reaction of 2-hydroxy-6-pentadecylbenzaldehyde with 3-chloro-1-benzothiophene-2-carboxylicacidhydrazide in the presence of glacial acetic acid in ethanol. The structure of this new compound was confirmed by elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectral analysis.     

Crystal Structure of Bis(3-hydroxy-2-pyridyl)disulfide

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＢｉｓ（３－ｈｙｄｒｏｘｙ－２－ｐｙｒｉｄｙｌ）ｄｉｓｕｌｆｉｄｅＣｈｅｎＸｕｅ－Ｔａｉ；ＫａｎｇＢｅｉ－Ｓｈｅｎｇ；ＸｕＹｏｎｇ－Ｊｉｎ；ＨｕＹｏｎｇ－Ｈａｎ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｔｒｕｃｔ...     

Das 1-(4-Hydroxyphenyl)-1-hydroxy-2-n-butylamino-?thansulfat (Vasculat)

Ohne Zusammenfassung     

Reaction of 5-aryl-4-acetyl-3-hydroxy-1-(ω-carboxyalkyl)-3-pyrrolin-2-ones with aromatic amines

Reactions of 5-aryl-4-acetyl-3-hydroxy-1-(ω-carboxyalkyl)-3-pyrrolin-2-ones with aromatic amines led to the formation of 5-aryl-4-(1-arylaminoethylidene)-1-(ω-carboxyalkyl)pyrrolidine-2,3-diones whose structure was confirmed by IR and ¹H NMR spectra and XRD analysis.     

2-Polyfluoroalkylchromones. 11. Synthesis and structures of 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-Δ2-pyrazolines and 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles

The reaction of 2-hydroxy-2-polyfluoroalkylchroman-4-ones with hydrazine affords 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-²-pyrazolines, whereas 2-polyfluoroalkylchromones under similar conditions produce 3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles. 5-(2-Hydroxyaryl)-1-methyl-3-polyfluoroalkylpyrazoles were synthesized in the reaction with methylhydrazine, and the reaction with phenylhydrazine afforded regioisomeric 3(5)-(2-hydroxyphenyl)-1-phenyl-5(3)-polyfluoroalkylpyrazoles.     

First synthesis of (R)-(−)-5-hydroxy-3-methyl-3-pyrrolin-2-one (jatropham) by lipase-catalyzed kinetic resolution

Jatropham, (R)-(−)-5-hydroxy-3-methyl-3-pyrrolin-2-one, is synthesized in three steps from citraconic anhydride. Highly regioselective reduction of citraconimide gives racemic jatropham in high yield. Kinetic resolution of racemic jatropham using lipase is also described.     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4′-hydroxy-3-methoxyphenyl)-7-(4′′-hydroxyphenyl)-3-heptanone

Diarylheptanoidsconstituteadistinctgroupofmetabolitesofnaturalplantcharacterizedbytwoaromaticringslinkedbyalinearsevenaliphaticchain.Therehavebeenfewreportsonthebiologicalactivitiesofdiarylheptanoids,mostofwhichappearingintheareasofanti-inflammatory,anti-oxidative,superoxidescavengingandanti-hepatotoxiceffects1,2.SomeofthemareusedastraditionalmedicineinAsia3.Compound1and2werefirstlyisolatedfromtherhizomesofZingiberofficalrespectively4,5.Sofarthesynthesisofthesetwocompoundshavenotbeenreportedy…     

Assessment of the absolute configuration of a series of (3R)-3-hydroxy-3-alkyl-β-lactams

The absolute stereochemistry of a series of (3R)-3-hydroxy-3-alkyl-β-lactams has been determined by circular dichroism and NMR spectroscopies. The sign of the circular dichroism band between 250 and 220 nm was related to the stereochemistry by applying the β-lactam sector rule. The NMR analysis unambiguously determines the relative configuration at C3 and C4 of the β-lactam ring. The reliability of the method has been proved by X-ray analysis of two of the examined compounds. The obtained results are in agreement with the mechanism proposed for the employed synthetic route.     

Reactions of Methyl 1-(Bromoacetyl)azulene-3-carboxylate with 2-Hydroxy-benzaldehydes: Synthesis of 1-(Benzofuran-2-yl)-3- methoxycarbonylazulenes

A few compounds containing the 2-arylbenzofuran nucleus, have been isolated from plants.[1] For example,moracins A and B, egonol, homoegonol and (±)-machicendiol are well known.     

Gram-scale synthesis of anti-pancreatic flavonoids (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-chrysin and -galangin

Gram-scale total synthesis of (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-galangin (1) and -chrysin (2) has been accomplished in eight steps from commercially available phloroglucinol and three steps from commercially available chrysin, respectively, featuring an efficient introduction of C(8) (1-prop-2-en-1-yl)phenyl moiety in the natural products through chemo- and regioselective cinnamylation and regioselective aromatic Claisen rearrangement.     

Abnormal Reaction of 1-(2′-Methoxybenzoyl)-1-(2′-hydroxy-5′-methoxycarbonylbenzoyl)methane Treated with Etyyl Orthoformate and Acetic Anhydride

邻羟基二苯甲酰基甲烷与Ａｃ２Ｏ和ＨＣ（ＯＥｔ）３反应通常是ＨＣ（ＯＥｔ）３作为酰化剂，得到３－苯甲酰基色酮。本文报道５－甲氧羰基－２－羟基苯甲酰基－（２′－甲氧苯甲酰基）甲烷与Ａｃ２Ｏ和ＨＣ（ＯＥｔ）３反应时，是Ａｃ２Ｏ而不是ＨＣ（ＯＥｔ）３作为酰化剂，生成３－苯甲酰基－２－甲基色酮。其结构经ＮＭＲ、ＭＳ、ＩＲ和ＥＡ证实。并对其反应机理作了讨论。     

Molecular Structure of 1- (Diisopropyl )amino-2-(p-methyl )phenyl-3-methyl-phosphetane 1-oxided

lINTR0DUCTIONThechemistryofstablephospheniumcati0n[Rl-P-R2j hasbeenextensivelyknowntl-3).Wereportedsynthesesandreactions0fthephospheniumcati0nsfeatur-ingwithanS-P-Nlinkage.(4-8)Recentlywefoundthatphospheniumion[i-Pr2N-P-Clj [AlC'j-canregiOselectivelyinsertintophenylcyclopropaneringattwocycliccarbon-carbonb0ndsadjacenttophenylgr0uptogivel-(diisopropyl)amin0-2-(p-methyl)phenyl-3-methyl-phosphetanel-oxide(1).Inordertodisclosetherelativesterelchemistry,itssinglecrystalwasobtainedfromn-he…     

Synthesis of 2[(1R,2R)-2-(2,4-Difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-triazol-yl)propyl]-4-[4-tetrafluoropropoxy)phenyl]-3-(2H,4H)-1,2,4-triazol-3-thione—A Novel and Potent Azole Antifungal Agent

A simple approach involving refluxing appropriately disubstituted thiosemicarbazide 8 in presence of formic acid for the synthesis of 1, a potent azole antifungal agent, has been described.     

Synthesis and characterization of α-{3-[2-hydroxy-3-(N-methyl-N-hydroxy-ethylamino)propoxy]propyl}-ω-butylpolydimethylsiloxanes.

α-{3-[2-hydroxy-3-(N-methyl-N-hydroxyethylamino)propoxy]propyl}-ω-butylpolydimethylsiloxanes Ⅲ with various moleculax weights were prepared by epoxy addition of α-[3-(2,3-epoxy-propoxy)propyl]-ω-butylpolydimethylsiloxanes Ⅱ and Nmethylmonoethanolamine.At each step.the outcome compounds were characterized through FT-IR and NMR spectra,the results showed that each step was successfully carried out and objective products were achieved.     

Rearrangement during halogenation of 2-hydroxy-1,2-diphenylpropan-1-one (α-methylbenzoin)

The reaction of 2-hydroxy-1,2-diphenylpropan-1-one 1 with SOCl₂ or PBr₃ gives, respectively, the 3-chloro- and 3-bromo-1,2-diphenylpropan-1-ones 4 and 6. The expected 2-chloro- and 2-bromo-1,2-diphenylpropan-1-ones 2 and 5 can, however, be formed by treatment of 1,2-diphenylpropan-1-one 8 with Cl₂ or Br₂/AlCl₃. The four halogenated products are characterised by ¹H and ¹³C NMR spectroscopy for the first time.